A woman is given assistance as people affected by the recent flooding in Japan rest at a makeshift shelter in Mabi, Okayama on July 11, 2018. (Credit: Martin Bureau/AFP/Getty Images)

Landslides and flooding caused by torrential rain in Japan have killed another 21 people in what has become one of the deadliest natural disasters to hit the country since the earthquake and tsunami at Fukushima in 2011.

A total of 176 people have been killed since the downpour began late last week, Japanese Chief Cabinet Secretary Yoshihide Suga said Wednesday. Another nine are missing.

Some 75,000 responders have been deployed to the area for search and rescue operations. Suga warned that thunderstorms and landslides in the coming hours could pose further danger.

Japanese Prime Minister Shinzo Abe was in Okayama Prefecture Wednesday morning, surveying the damage in one of the hardest-hit areas.

He viewed the damage from above in a helicopter and visited an evacuation center. He’s expected to visit the devastated city of Kurashiki and meet with the Okayama governor later Wednesday.

Soldiers push a boat as they prepare to search for survivors following heavy flooding, on July 8, 2018 in Kurashiki near Okayama, Japan. (Credit: Carl Court/Getty Images)

Hundreds of thousands of people were forced to flee their homes, and those unable to leave took shelter on rooftops during the heavy flash flooding that hit the country’s streets.

Japanese public broadcaster NHK reported about 364 millimeters (14.3 inches) of rain fell between 5 a.m. and 7 a.m. Sunday in the city of Uwajima — approximately 1.5 times the average monthly rainfall for July.

In Sukumo City in Kochi prefecture, 263 millimeters (10.3 inches) of rain fell in two hours, NHK said.

More than 20,000 people were killed or went missing during the Fukushima disaster, when a 9.0-magnitude earthquake hit Japan, triggering a tsunami and nuclear meltdown at the Fukushima nuclear plant.